Physconia grumosa, a species previously known from Asia, is reported from Alaska, the Rocky Mountains (Colorado, New Mexico), New England (Maine) and the Great Lakes region (Michigan, Minnesota, Wisconsin, Ontario). This species is similar to P. detersa, differing primarily by the type of propagules formed along the lobe margins: granular to weakly coralloid isidia and few to many dorsiventral lobules instead of true soredia. A description of the species is provided and comparisons with similar species are given.